Brake



July 10, 1928.

- A. c. woLLENsAK l-:T AL

BRAKE' 2 sheds-sheet 2 Fued Feb; 5, 1926 Patented July 10, 1928. I. .Y NTED STATES ARTHUR C. wOLLENsAK. ANTON, :reco-Bs',

i BRA twain i AND PAULA CfBALntTs, or MILWAIIKEE, WISCONSIN, AssrGNoRs To STERLING MOTOR TRUCK COMrANY, on MILWAUKEE, 'w'.IsoONsIN,I A CORPORATION OF WISCONSIN.

Application ined rebruary 5, 192e. seriai No, 86,202.

This invention relates to brakes, andl is particularly directed to a jack shaft brake for automotive vehicles. 1

Objects of this invention areto Aprovide a channel construction throughout the supporting bracket and the brake to secure the maximumy strength with the minimum iwf-eight oflma-terial.- s j 'l Further objects are to providea construc-f tion 'of brake which will afford wide bea-r-` ing surfaces for the brake shoe both for contact with the brakevdrum, and also for contact with the supporting pins so that the wearis reduced toa minimum.

Further objects are to provide toggle mechanism for operating the'brakes with n the mechanism positioned in alignment with the brake operating arms and directly beneath the supporting piny for the brake operating levers. 1

Further objects are to provide a novel; means of carrying the brake shoes upon the brake levers to permit the uniform application of pressure throughout the entire area of the brake shoes andl al'soto insurea complete disengagement ofthe brake shoes from the brake drum throughout the entire eX- tent of the brake shoes, although the brake lever may be pivo-tedfat a single point.

An embodiment vof* the inventionfis shown in the accompanying drawings, in which f Figure l is a View partly, in section show-y ing a side elevation of the'brake as itap-v pears when att-ached to the truck.

lFigure 2 is a face view of the brakes with` parts broken away. Y i

Figure 3 is a sectionaly View onthe'linel 3-3 of Figure 2;

` Referring to the drawings, it' will be seen, c

particularly from reference to Figure 1, thatl the brake comprises aj'channel bracket-"1 which has attaching arms or flanges'Q bolted tofthe side frame bars 3 of the truck.` This construction is duplicated onA opposite sides of the truck and need not, there-fore, :bef repeated in the illustration. f It is to be noted from Figure 1, that the channel bracketll has wide webs 4' which are roughly triangular and` extend ydownwardly to the attaching flange 2.v Further, this bracket is provided with'bearings 5 and G for the rock shaft 7 which `operates the brake.

rThe outer end fof the bracket is provided with an outer bearing boss or llug 8 andan inner bearing boss or lug 9 .which carry the main supporting pin 10 for the brake levers. These brake levers are indicated at .11 and 12 in Figure 2 and from referencevto Figure 1,

it willbe seen thatr their upper ends are intermeshed at th-e point `where yt-he pin'lOf passes therethrough. These upper ends are.

positioned between the bearings Sand 49, as`

illustrated in Figure 1 *l The" brake l'eversare approximately arch-1 shaped and extend downwardly and ins the triangular bell crank lever '1'3is com" necte'd by means of al link or pitman 15 Vwith they forked lower -endjof the lever It is to be noted that the rod 15 extends through the relatively large pin 16 carried in the forkedE lower end off the lever 1.2. Theaouter end of the rod 15 is threaded and carries the crank lever-13 is connected vby .means'of link 18 with a short armorlever 19 carried by the rock' shaft 7 1 Itis to be notedf-fromY s Figure 1 that the link` 18fsl'antsinwardly towards the truck thus avoiding along over hangr for` the shaft' 7 fand positioning' fthe' short lever or arm'19 close to the bearing(5.` The 'rock yshaft 7 may be operated in any suitablemannergas by means of the curvedy levery 20 (seeF'igure 1), such lever lbeingf" connected to the-brake pedal by meansvo'f'the Alink22 (see Figure 2,) V

It is to be noted upon referenceA to Fig#` ures 1 andf Q'tliat the brake levers arechan-1.1

nel-shapedY throughout and thus the maxi?,`

mum strength withv the minimum ofwei'ght`r` is attained. This' construction'is followed ,inf the4 brake shoes 28 and' 242. Forexample, from reference to Figure 3, it'will beseen l that the bra-ke shoesare also channel-shaped and enclose the channel-shaped brake levers.

They are "pivotedl centrally of their extentl toE ioo thebra'ke'llevers by means 'ofpins25- `YIhese' i brake shoes conformv accuratelyv 'toi the v .pea-

ripher-y `of the `jack shaft 'drum or brake drum "QGand are lined in' any suitablemanner. y

In order to insure the uniform spacing Ofthe brake shoes from the brake drum when the brake is open, a novel construction is provided. e' A set screw 27 extends through cach of the brake levers and projects to- Y wards the brake shoes.

These set screws are positioned above the pins 25, as shown in Figure 2. Further, a small spring 28 is socketed within suitable recesses in the brake shoes and inthe brake levers, as shownA on the Yleft hand side of Figure 2. These i springs are mounted below the pins 25 and rock the brake` shoes into contact with `the set screws Q7. Thus when the brake levers are opened outwardly the brake shoes tilt and move away from the brake drum so as to be uniformly spaced therefrom at their top and bottom portions although the brake levers are vpivoted at their upperends upon a single pin 10. y.

Vhen the pressure isV applied by means of the mechanism previously described, the brake shoes '23 and 24 independently rock upon the pins and accurately conform to the brake drum 26. Further, by this means, the pressure is uniformly applied to the brake drums throughout the extent vof the brake shoes. A i

One of 'the brake levers, for instance the brake lever l1, may lcarry a pin 29 which l lprojects towards the truck and which is attached to one end of a spring 30. The

i other end of the spring 30 is attached to any stationary portion` of the apparatus, such for instance as a lug 31 projecting downwardly from thebearing 6.

It is, of course, to be understoodV that the jackfshai't is rigidly attached to any suitable orm of drive such, for instance, as the driving pinion or sprocket wheel 32 which is connected in the usual mannerby means of a chain with a corresponding sprocket wheel on the rearaxle, or` rear wheel of the machine. Y

hlt is to be noted further that the arm for supporting the bearing 6` carries an outwardly projecting arm 33 whichoverhangs the brake lever 11. This arm 33 is provided with a set screw 34 equippedwith a suitable.'

look nut. The set screw 34 projects inwardly towards ythe brake lever l1 and limits the outward motion of this lever. Thuswhen the brake is open it isimpossible for the rentire mechanism to'swing back and yforth and alternately contact with opposite sides of the brake drum. 11 opens outwardly until it contacts with the set screw 34. Further opening ofV the f brakecauses the other lever to4 move outwardly and thus insures a correct spacing of both'brake shoes from the brake drum.

It will be seen that a novel `form of jack shaft brake has been provided which may be most rigidly attached to and supported from the -side frame bars of a truck, and it will be seen further that due to ther channel Instead, the lever construction of bracket, brake levers and brake shoes that the maximum strength and compactness is secured, together j with a minimum weight.

It is to be noted further that the peculiar way in which the brake shoes are mounted i insures a unitorin pressurethroughout their extent upon the brakedrum irrespective of wear in the shoes and irrespective of the single pivot point 'for the brake levers. Further, it is to be particularly noted that when the brake is opened that the brake shoes.

move away from the brake 'drum throughout their entire extent. l n

. It is to be noted further that novel means have been. provided for vpreventing the' swinging of the entire` ybrake mechanism back and forth with consequent contacting with or. rubbing `against the brake drum.

Instead, inthe practice of this invention means are provided tor insuring-the holding of the brakeshoes out of Contact with the drum. j y

Although the ,invention hasqbeen described in considerable detail, itis to be understood that the inventionmay be vari-V ously embodied and is, therefore,l to be j limited only as claimed. y.

.Ve claim: f r

A jack shaft brake for automotive vehicles provided with a jack shaft brakedrum, said brake comprising a channel-shaped bracket attached to the side frame .barof the automotive vehicle and projecting outwardly above said brake drum and having a pair of spacedl bearings, a pin.- carried between said bearings, a pair of channel-shaped brake levers having intermcshing upper pivotallyy mounted upon said pin, a pair of channel-shaped brake shoes enclosing a portion of said brake levers and pivoted intermediate thefends of said shoes to said brake levers, said brake shoes being adapted to" grip the brake drum between them, kset screwscarried :by each of said brake levers and limiting the swinging motion of the brake shoes in one direction, springs interposed betwen said brakey shoes and brake levers andy tending toswing such brake shoes into contact with the set screws, abell crank lever pivoted to one of said brake levers and connected to the other of said brake State of `Visconsin.

ARTHUR o. woLLnNsAK.

ANTON JACOBS. PAUL o. eiiiiniisu ends 

